1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* linux/drivers/spi/spi_s3c24xx_fiq.S
4 * Copyright 2009 Simtec Electronics
5 * Ben Dooks <ben@simtec.co.uk>
7 * S3C24XX SPI - FIQ pseudo-DMA transfer code
10 #include <linux/linkage.h>
11 #include <asm/assembler.h>
16 #include <linux/spi/s3c24xx-fiq.h>
18 #define S3C2410_SPTDAT (0x10)
19 #define S3C2410_SPRDAT (0x14)
23 @ entry to these routines is as follows, with the register names
24 @ defined in fiq.h so that they can be shared with the C files which
25 @ setup the calling registers.
27 @ fiq_rirq The base of the IRQ registers to find S3C2410_SRCPND
28 @ fiq_rtmp Temporary register to hold tx/rx data
29 @ fiq_rspi The base of the SPI register block
30 @ fiq_rtx The tx buffer pointer
31 @ fiq_rrx The rx buffer pointer
32 @ fiq_rcount The number of bytes to move
34 @ each entry starts with a word entry of how long it is
35 @ and an offset to the irq acknowledgment word
37 ENTRY(s3c24xx_spi_fiq_rx)
38 .word fiq_rx_end - fiq_rx_start
39 .word fiq_rx_irq_ack - fiq_rx_start
41 ldr fiq_rtmp, fiq_rx_irq_ack
42 str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ]
44 ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ]
45 strb fiq_rtmp, [ fiq_rrx ], #1
48 strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ]
50 subs fiq_rcount, fiq_rcount, #1
51 subsne pc, lr, #4 @@ return, still have work to do
53 @@ set IRQ controller so that next op will trigger IRQ
55 str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ]
62 ENTRY(s3c24xx_spi_fiq_txrx)
63 .word fiq_txrx_end - fiq_txrx_start
64 .word fiq_txrx_irq_ack - fiq_txrx_start
67 ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ]
68 strb fiq_rtmp, [ fiq_rrx ], #1
70 ldr fiq_rtmp, fiq_txrx_irq_ack
71 str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ]
73 ldrb fiq_rtmp, [ fiq_rtx ], #1
74 strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ]
76 subs fiq_rcount, fiq_rcount, #1
77 subsne pc, lr, #4 @@ return, still have work to do
80 str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ]
88 ENTRY(s3c24xx_spi_fiq_tx)
89 .word fiq_tx_end - fiq_tx_start
90 .word fiq_tx_irq_ack - fiq_tx_start
92 ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ]
94 ldr fiq_rtmp, fiq_tx_irq_ack
95 str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ]
97 ldrb fiq_rtmp, [ fiq_rtx ], #1
98 strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ]
100 subs fiq_rcount, fiq_rcount, #1
101 subsne pc, lr, #4 @@ return, still have work to do
104 str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ]